In recent years, fuel efficiency has been strongly sought from automobile tires due to environmental issues and resource issues. A tire obtained by using a rubber composition containing silica is better in low heat buildup compared with a tire obtained by using the usually used rubber composition including carbon black, so it is possible to produce a tire excellent in fuel efficiency using this.
For example, Patent Document 1 discloses a tire-use rubber composition comprising a conjugated diene polymer obtained by copolymerization of a conjugated diene compound etc. with a vinyl compound having a predetermined heteroatom-containing functional group into which silica and a silane coupling agent are added. However, in the art specifically described in Patent Document 1, a vinyl compound having a predetermined heteroatom-containing functional group is copolymerized with so as to improve the affinity of the conjugated diene polymer with silica, but the effect of improvement of the affinity with silica obtained by introduction of the vinyl compound having a predetermined heteroatom-containing functional group is limited. For this reason, in this art, the performance expected to be improved by improvement of the affinity with silica, specifically the low heat buildup, is not necessarily sufficient.